Schott: high refractive lenses with precision moulding process

Schott has patented a precision moulding process for producing strips and arrays of high refractive miniature lenses out of glass, in response to the increase in demand for high-brightness Light Emitt…

Schott has patented a precision moulding process for producing strips and arrays of high refractive miniature lenses out of glass, in response to the increase in demand for high-brightness Light Emitting Diodes (LED). Glass types such as P-LaSF47 enable compact light source dimensions with high light throughputs for wavelengths ranging from 350 to 2,000 nm. From medical technology to high-power spotlights, such as those used for stage illumination and architectural lighting, automotive lighting or UV applications – glass allows for compact solutions in lighting and optics. It offers high light throughput, yet is insensitive to heat, moisture and UV-radiation. These lenses can have a very high and steep curvature and be placed very closely together, says Dr. Ralf Biertmpfel, application manager at Schott in Mainz. This makes them particularly attractive for light sources with several LEDs, for instance. Strips and arrays of lenses are much easier to process and mount than individual lenses, he adds. For example, 19 aspherically formed lenses 5mm in diameter and 2.5mm in height can be combined on an array that is only 25mm in diameter. The process also allows for other supply forms such as diffractive optical elements and Fresnel lenses, as well as free combinations of several designs. In addition, this process can be used to produce hybrid optical components, says Biertmpfel. We are able to form and melt together two or more optical materials at the same time using only one process step. This opens up entirely new options for further exploring the cost-efficient miniaturization of optical systems, he adds. Schott designed the Low Tg glasses P-LaSF47 (nd = 1.8016), N-LaF33 (nd = 1.7821), P-SK57 (nd = 1.5843) and N-FK5 (nd = 1.4850) especially for use in precision molding. They have a low transformation temperature (Tg) of below 550C and are ideally suited for use in producing high refractive optical components. Just recently Schott extended its portfolio on low Tg glasses. The following glass types – preferably in form of rods – are now available: P-SF68 (nd = 2.0052), P-LASF51 (nd = 1.8100), P-LASF50 (nd = 1.8086), P-LAK35 (nd = 1.694), P-SK60 (nd = 1.6104) and P-SK58A (nd = 1.5891).